RESEARCH STARTER

Medical physics

Medical physics is a specialized field that applies principles of physics to the realm of medicine, particularly in the areas of clinical measurement, diagnosis, and treatment of health disorders. This discipline primarily functions within hospitals and academic institutions, where professionals known as medical physicists operate in departments such as radiology, nuclear medicine, and radiotherapy. The historical roots of medical physics can be traced back to ancient practices, with significant contributions from notable figures like Hippocrates and Ibn al-Haytham, who explored diagnostic techniques and the properties of vision, respectively.

The field gained substantial recognition in the nineteenth century with advancements in physiological measurements and the pivotal discovery of X-rays by Wilhelm Röntgen in 1895, which revolutionized medical imaging. Over the decades, medical physics has evolved into its own profession, with practitioners focusing on areas such as radiation safety and imaging technology, including CT scans, PET scans, and MRI. By the twenty-first century, medical physicists had become integral to hospital operations, leveraging innovations in electronics and computer technology to enhance diagnostic capabilities and treatment modalities. This continuous interplay between physics and medicine highlights the importance of medical physics in improving patient care and advancing healthcare technology.

Full Article

Medical physics is an area of medicine that applies the methods and theories of physics—the scientific study of matter, energy, force, and motion—to medical care. Medical physics plays a role in clinical measurement, diagnosis, and treatment of various health disorders. Medical physics is primarily utilized in a hospital or academic setting, and professionals known as medical physicists work in designated departments within these institutions. Medical physicists most commonly work in the fields of radiology, nuclear medicine, radiotherapy, and related sciences. Although the discipline did not see rampant innovation until the nineteenth century, studies of how physics applies to medicine can be traced back to ancient Egypt.

Background

Depending on how the scope of medical physics is defined, the discipline may date back anywhere from 5,000 to one hundred years ago. Physical methods were used by physicians to treat injuries and disease as far back as ancient Egypt. The Edwin Smith Papyrus, an Egyptian document dating between 3000 and 2500 BCE, describes doctors treating breast sores with cauterization, a method that uses a heated instrument to seal a wound and destroy infected tissue.

Centuries later, Greek physician Hippocrates documented the first known methods for measuring a person’s body temperature. Hippocrates used an early observational method to estimate body temperature, which differs significantly from modern method of thermography, which records a visual image of the infrared radiation emitted from the body’s heat production. Higher temperatures are more visible as infrared radiation in thermographic scans, making it possible to diagnose diseases or locate tumors more easily. Hippocrates’s technique also used visuals to identify higher body temperatures. His method covered a person’s thorax with a cloth soaked in clay. People with high body temperatures dried the clay faster than those with regular temperatures. The speed at which the cloth dried helped Hippocrates determine the patient’s body temperature. Many historians consider Hippocrates’s method to be the earliest example of diagnostic testing.

More examples of the use of physics in medicine appeared throughout the next several centuries. In the second century CE, Greek priests used magnetic rings to treat arthritis, a method that would prove ineffective in the modern era. Throughout the medieval period, a number of prominent thinkers experimented with physics and medicine. Tenth-century Iraqi polymath Ibn al-Haytham made significant contributions to the science of optics, or the study of light. Al-Haytham outlined the physical properties of vision. He demonstrated that vision occurs when rays of light enter the eye, not by light emitting from the eye, as many believed. Italian Renaissance artist Leonardo da Vinci also contributed to the study of optics during his lifetime. He has made significant contributions to anatomy and biomechanics through detailed observational studies, which later influenced fields related to medical physics.

A historical shift known as the Scientific Revolution occurred in the seventeenth century. This period marked the introduction of the scientific method, a series of methods used to obtain knowledge about the natural world. It also introduced new technologies, such as the microscope. By the end of the Scientific Revolution, science had replaced religion and philosophy as the primary source of understanding about nature. A number of scientific disciplines arose that furthered knowledge of human mechanics. Scientists discovered the importance of the human heart in pumping blood throughout the body and how this blood circulated. A field known as latrophysics—a term derived from the Greek word for physician and often translated as medical physics—studied bodily functions and the nature of life. From this discipline, a number of subdisciplines emerged, including biomechanics and electrophysiology. By the nineteenth century, the modern notion of medical physics was beginning to take shape.

Overview

The nineteenth century saw rapid advances in the science of physiological measurements. Studies in the mechanical, electrical, thermal, acoustical, and optical processes that occur inside the body led to better methods of clinical measurement, diagnosis, and treatment in the medical field. The medical community took notice of the importance physics played in medical education and began incorporating physics studies into undergraduate curriculums. Some medical schools established their own academic physics departments to ensure students had access to these teachings.

As time went on, medical physics was considered less a standard part of medical education and more its own course of study, although a number of advancements in medical physics were completed by scientists who were not medical physicists. Medical physics reached a turning point in 1895 with the discovery of X-rays by Wilhelm Röntgen. Röntgen’s discovery had a great deal of potential as a diagnostic tool for the medical community. X-rays were explored for both diagnostic imaging and experimental therapeutic treatment for issues such as lesions, but the technology set the scene for rapid progress in the medical imaging field and led to the establishment of radiology in medicine. As radiation became an apparent issue when carrying out X-rays, studies in radiation protection were undertaken to work toward preventing any harmful effects.

By the twentieth century, the field of medical physics was being recognized as an important facet of hospital operations, and many hospitals began employing medical physicists to support clinical activities. Continued research led to the development of other X-ray-based imaging methods, such as computed tomography (CT) scans and positron emission tomography (PET) scans. Medical physics technology innovations surged following the end of World War II (1939–1945) with the developments in nuclear physics made during the war. Ultrasound technology, which uses high-frequency sound waves to create images of internal organs, became a standard and non-invasive approach to clinical diagnoses. The 1970s saw the invention of the magnetic resonance imaging (MRI) scan, which uses strong magnetic fields and radio waves to form pictures of the body’s interior.

Continued advances in medical physics related to the areas of electronics and computer technology further transformed the way the medical community diagnosed and treated health issues. By the twenty-first century, medical physics was its own profession, specializing in the medical applications of physics. Medical physicists focused on the sciences of radiology, radiotherapy, radiation safety, and nuclear medicine. Most were employed by hospitals and other medical facilities, while others worked in government or higher education. After 2020, advancements in this field include the integration of artificial intelligence in medical imaging, improving diagnostic accuracy and efficiency.


Bibliography

Brown, B.H., et al. Medical Physics and Biomedical Engineering. Taylor & Francis, 2017.

Duck, F. “The Origins of Medical Physics.” European Journal of Medical Physics, vol. 30, no. 4, 2014, pp. 397–402.

Keevil, Steven F. “Physics and Medicine: A Historical Perspective.” Lancet, vol. 379, no. 9825, 2012, pp. 1517–24.

Laughlin, John S. “History of Medical Physics.” Physics Today, vol. 36, no. 7, 1983, pp. 26–33.

“Leonardo da Vinci.” Encyclopaedia Britannica, www.britannica.com/biography/Leonardo-da-Vinci. Accessed 1 Apr. 2026.”Medical Physicist.” American Association of Physicists in Medicine, www.aapm.org/medical_physicist. Accessed 1 Apr. 2026.

National Center for Biotechnology Information. “Hippocratic Thermography.” U.S. National Library of Medicine, www.ncbi.nlm.nih.gov/books/NBK546707/. Accessed 1 Apr. 2026.

National Center for Complementary and Integrative Health. “Magnets for Pain: What You Need to Know.” National Center for Complementary and Integrative Health, www.nccih.nih.gov/health/magnets-for-pain-what-you-need-to-know. Accessed 1 Apr. 2026.

National Institute of Biomedical Imaging and Bioengineering. “Magnetic Resonance Imaging (MRI).” www.nibib.nih.gov/science-education/science-topics/magnetic-resonance-imaging-mri. Accessed 1 Apr. 2026.

National Institutes of Health. “Artificial Intelligence Improves Medical Imaging.” www.nih.gov/news-events/nih-research-matters/artificial-intelligence-improves-medical-imaging. Accessed 1 Apr. 2026.

Otsuka, K., and T. Togawa. “Hippocratic Thermography.” Physiological Measurement, vol. 18, no. 3, 1997, pp. 227–32.

Pollard-Larkin, Julianne. “Med Phys Workforce: Where Have All of the Physicists Gone and How to Keep the Ones You Have?” ASTRONews, 2024, www.astro.org/news-and-publications/astronews/2024/summer-astronews/features/med-phys-workforce. Accessed 1 Apr. 2026.

“Radiation Dose in X-Ray and CT Exams.” RadiologyInfo.org, www.radiologyinfo.org/en/info/safety-xray. Accessed 1 Apr. 2026.

Webb, Steve. “The Contribution, History, Impact and Future of Physics in Medicine.” Acta Oncologica, vol. 48, no. 2, 2009, pp. 169–77.

“What Is Medical Physics?” Canadian Organization of Medical Physicists, www.comp-ocpm.ca/english/about-comp/what-is-medical-physics/what-is-medical-physics.html. Accessed 1 Apr. 2026.

Full Article

Medical physics is an area of medicine that applies the methods and theories of physics—the scientific study of matter, energy, force, and motion—to medical care. Medical physics plays a role in clinical measurement, diagnosis, and treatment of various health disorders. Medical physics is primarily utilized in a hospital or academic setting, and professionals known as medical physicists work in designated departments within these institutions. Medical physicists most commonly work in the fields of radiology, nuclear medicine, radiotherapy, and related sciences. Although the discipline did not see rampant innovation until the nineteenth century, studies of how physics applies to medicine can be traced back to ancient Egypt.

Background

Depending on how the scope of medical physics is defined, the discipline may date back anywhere from 5,000 to one hundred years ago. Physical methods were used by physicians to treat injuries and disease as far back as ancient Egypt. The Edwin Smith Papyrus, an Egyptian document dating between 3000 and 2500 BCE, describes doctors treating breast sores with cauterization, a method that uses a heated instrument to seal a wound and destroy infected tissue.

Centuries later, Greek physician Hippocrates documented the first known methods for measuring a person’s body temperature. Hippocrates used an early observational method to estimate body temperature, which differs significantly from modern method of thermography, which records a visual image of the infrared radiation emitted from the body’s heat production. Higher temperatures are more visible as infrared radiation in thermographic scans, making it possible to diagnose diseases or locate tumors more easily. Hippocrates’s technique also used visuals to identify higher body temperatures. His method covered a person’s thorax with a cloth soaked in clay. People with high body temperatures dried the clay faster than those with regular temperatures. The speed at which the cloth dried helped Hippocrates determine the patient’s body temperature. Many historians consider Hippocrates’s method to be the earliest example of diagnostic testing.

More examples of the use of physics in medicine appeared throughout the next several centuries. In the second century CE, Greek priests used magnetic rings to treat arthritis, a method that would prove ineffective in the modern era. Throughout the medieval period, a number of prominent thinkers experimented with physics and medicine. Tenth-century Iraqi polymath Ibn al-Haytham made significant contributions to the science of optics, or the study of light. Al-Haytham outlined the physical properties of vision. He demonstrated that vision occurs when rays of light enter the eye, not by light emitting from the eye, as many believed. Italian Renaissance artist Leonardo da Vinci also contributed to the study of optics during his lifetime. He has made significant contributions to anatomy and biomechanics through detailed observational studies, which later influenced fields related to medical physics.

A historical shift known as the Scientific Revolution occurred in the seventeenth century. This period marked the introduction of the scientific method, a series of methods used to obtain knowledge about the natural world. It also introduced new technologies, such as the microscope. By the end of the Scientific Revolution, science had replaced religion and philosophy as the primary source of understanding about nature. A number of scientific disciplines arose that furthered knowledge of human mechanics. Scientists discovered the importance of the human heart in pumping blood throughout the body and how this blood circulated. A field known as latrophysics—a term derived from the Greek word for physician and often translated as medical physics—studied bodily functions and the nature of life. From this discipline, a number of subdisciplines emerged, including biomechanics and electrophysiology. By the nineteenth century, the modern notion of medical physics was beginning to take shape.

Overview

The nineteenth century saw rapid advances in the science of physiological measurements. Studies in the mechanical, electrical, thermal, acoustical, and optical processes that occur inside the body led to better methods of clinical measurement, diagnosis, and treatment in the medical field. The medical community took notice of the importance physics played in medical education and began incorporating physics studies into undergraduate curriculums. Some medical schools established their own academic physics departments to ensure students had access to these teachings.

As time went on, medical physics was considered less a standard part of medical education and more its own course of study, although a number of advancements in medical physics were completed by scientists who were not medical physicists. Medical physics reached a turning point in 1895 with the discovery of X-rays by Wilhelm Röntgen. Röntgen’s discovery had a great deal of potential as a diagnostic tool for the medical community. X-rays were explored for both diagnostic imaging and experimental therapeutic treatment for issues such as lesions, but the technology set the scene for rapid progress in the medical imaging field and led to the establishment of radiology in medicine. As radiation became an apparent issue when carrying out X-rays, studies in radiation protection were undertaken to work toward preventing any harmful effects.

By the twentieth century, the field of medical physics was being recognized as an important facet of hospital operations, and many hospitals began employing medical physicists to support clinical activities. Continued research led to the development of other X-ray-based imaging methods, such as computed tomography (CT) scans and positron emission tomography (PET) scans. Medical physics technology innovations surged following the end of World War II (1939–1945) with the developments in nuclear physics made during the war. Ultrasound technology, which uses high-frequency sound waves to create images of internal organs, became a standard and non-invasive approach to clinical diagnoses. The 1970s saw the invention of the magnetic resonance imaging (MRI) scan, which uses strong magnetic fields and radio waves to form pictures of the body’s interior.

Continued advances in medical physics related to the areas of electronics and computer technology further transformed the way the medical community diagnosed and treated health issues. By the twenty-first century, medical physics was its own profession, specializing in the medical applications of physics. Medical physicists focused on the sciences of radiology, radiotherapy, radiation safety, and nuclear medicine. Most were employed by hospitals and other medical facilities, while others worked in government or higher education. After 2020, advancements in this field include the integration of artificial intelligence in medical imaging, improving diagnostic accuracy and efficiency.


Bibliography

Brown, B.H., et al. Medical Physics and Biomedical Engineering. Taylor & Francis, 2017.

Duck, F. “The Origins of Medical Physics.” European Journal of Medical Physics, vol. 30, no. 4, 2014, pp. 397–402.

Keevil, Steven F. “Physics and Medicine: A Historical Perspective.” Lancet, vol. 379, no. 9825, 2012, pp. 1517–24.

Laughlin, John S. “History of Medical Physics.” Physics Today, vol. 36, no. 7, 1983, pp. 26–33.

“Leonardo da Vinci.” Encyclopaedia Britannica, www.britannica.com/biography/Leonardo-da-Vinci. Accessed 1 Apr. 2026.”Medical Physicist.” American Association of Physicists in Medicine, www.aapm.org/medical_physicist. Accessed 1 Apr. 2026.

National Center for Biotechnology Information. “Hippocratic Thermography.” U.S. National Library of Medicine, www.ncbi.nlm.nih.gov/books/NBK546707/. Accessed 1 Apr. 2026.

National Center for Complementary and Integrative Health. “Magnets for Pain: What You Need to Know.” National Center for Complementary and Integrative Health, www.nccih.nih.gov/health/magnets-for-pain-what-you-need-to-know. Accessed 1 Apr. 2026.

National Institute of Biomedical Imaging and Bioengineering. “Magnetic Resonance Imaging (MRI).” www.nibib.nih.gov/science-education/science-topics/magnetic-resonance-imaging-mri. Accessed 1 Apr. 2026.

National Institutes of Health. “Artificial Intelligence Improves Medical Imaging.” www.nih.gov/news-events/nih-research-matters/artificial-intelligence-improves-medical-imaging. Accessed 1 Apr. 2026.

Otsuka, K., and T. Togawa. “Hippocratic Thermography.” Physiological Measurement, vol. 18, no. 3, 1997, pp. 227–32.

Pollard-Larkin, Julianne. “Med Phys Workforce: Where Have All of the Physicists Gone and How to Keep the Ones You Have?” ASTRONews, 2024, www.astro.org/news-and-publications/astronews/2024/summer-astronews/features/med-phys-workforce. Accessed 1 Apr. 2026.

“Radiation Dose in X-Ray and CT Exams.” RadiologyInfo.org, www.radiologyinfo.org/en/info/safety-xray. Accessed 1 Apr. 2026.

Webb, Steve. “The Contribution, History, Impact and Future of Physics in Medicine.” Acta Oncologica, vol. 48, no. 2, 2009, pp. 169–77.

“What Is Medical Physics?” Canadian Organization of Medical Physicists, www.comp-ocpm.ca/english/about-comp/what-is-medical-physics/what-is-medical-physics.html. Accessed 1 Apr. 2026.

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